Map of Lac des Grandes Baies with depth contours

Lac des Grandes Baies

46.378° N, 75.11° W

Depth contours from the 2012 government survey. Not for navigation.

Download the depth map (SVG)

Lac des Grandes Baies is 49.5 m deep at its deepest point, deeper than 93% of the 1,506 surveyed lakes in Quebec. It covers 3.57 km² and lies 1.8 km south of Montigny.

Maximum depth
49.5 msurveyed 2012
deeper than 93% of the 1,506 surveyed lakes in Quebec
Area
3.57 km²
larger than 88% of the 29,407 lakes in Quebec
Shoreline
37.2 km
longer than 94% of the 29,407 lakes in Quebec
Water clarity
4.1 mSecchi depth, 2024
clearer than 55% of the 805 monitored lakes in Quebec
Elevation
264 m

Today on the water

6.2 °C

Wind W 3 km/h

Observed at Mont-Laurier, as of 2:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.2 m.

Hourly forecast, next 24 hours
Time3 a.m.6 a.m.9 a.m.12 p.m.3 p.m.6 p.m.9 p.m.12 a.m.
Wind km/hW 10W 10W 10NW 20NW 20NW 15NW 10var. 5
Waves (est.) m0.10.10.10.2
Temp. °C54589731
Precip. %6030303030000

Tonight: Mainly cloudy with 60 percent chance of showers. Wind west 20 km/h becoming light this evening. Low plus 4.

Weather: Mont-Laurier (local forecast), as of 2:02 a.m. EDT

Sun and moon

Civil dawn
6:39 a.m.
Sunrise
7:09 a.m.
Sunset
6:24 p.m.
Civil dusk
6:54 p.m.
Moonrise
6:00 a.m.
Moonset
5:43 p.m.
Moon
Waning crescent, 1% lit

Data Source: Environment and Climate Change Canada. Local times.

How waves are estimated

Significant wave height from the forecast hourly wind and the open-water distance (fetch) upwind, using the SMB method (US Army Corps of Engineers Shore Protection Manual, 1984), rounded up to the next 0.1 m. It is not a measurement: gusts, leftover swell and shoals can make water rougher. Under 0.2 m: calm; 0.2–0.5 m: choppy; over 0.5 m: rough.

Depth

22% of Lac des Grandes Baies is deeper than 20 m.

How to read it: the lake’s area is sorted from the shore to the deepest point. Where the curve is flat, large areas share one depth (flats and weed beds); where it drops, depth changes quickly (drop-offs).

The government depth survey from 2012 records a maximum depth of 49.5 m, drawn from 66 depth contours.

Not for navigation. Depths are from government surveys and may be outdated.

Water

Trophic status from the latest monitoring: oligo-mesotrophic (transition).

Clarity was measured with a Secchi disk in 5 years between 2004 and 2024; the latest annual mean is 4.1 m.

Water clarity (Secchi depth, m)
Total phosphorus (µg/L)